Instrument housing



y 1957 F. w. TRUESDELL ET AL 2,800,248

INSTRUMENT HOUSING Filed Nov. 8, 1954 Fig.6

United States Patent 6 2,800,243 INSTRUMENT HOUSING Francis w.Truesdell, Dover, N. H., and Carl F. Van Bennekom, Lynnfieid, Mass,assignors to General Electric Company, a corporation of New YorkApplication November 8, 1954, Serial No. 467,404 i 4 Claims. (Cl.220-55) on such housings may be selectively clamped in place or removedtherefrom as desired.

In the art of instrumentation there are many applications for a housingincluding a receptacle and a .cover removably positioned over an openingin such a receptacle, and it is often desirable to provide simple andeffective means in such a housing to permit ready removal of the cover.For example, in the time switch art, such devices are in many instancesenclosed within a weatherproof housing and are provided with a removablecover to permit selective setting of the switch for any predeterminedtime of the day. In the case of those switches that have their controlsetting frequently changed, the structure utilized for assembly andremoval of the cover should be as simple as possible to permit changesin setting with a minimum of difficulty.

Briefly, the invention contemplates in one aspect thereof an arrangementof a receptacle and cover and a pivotally mounted clamping member in theform of a wire handle or bail that is selectively movable between anon-clamping and a clamping position by simple-pivotal motion. The wirehandle is preferably made of a resilient deformable material, such as astiff steel, and positive locking of the cover is achieved through aspecial camming arrangement that automatically moves the clampingportions of the handle into a position directly over a portion of thecover, after which the handle maybe moved to its clamping positionduring which suificient forces are developed in the wire to forciblypress it downwardly into the cover. The handle is slightly deformedwhile held in the clamping position, but it immediately returns to itsoriginal form upon release of the clamping forces.

A gasket may be used with the housing and the clamping forces developedby the improved clamping arrangements are effectively used to give aweatherproof seal between the cover and the receptacle.

Another feature of the design is the arrangement whereby the handle hasto be moved through nearly its entire pivotal path to be in properposition for removal of the cover, and until it is moved to thatposition there is no danger of the cover accidentally coming off.

For all usual installation positions of instrument housings embodyingthe novel clamping arrangement, the cover can be easily removed andreplaced with only one hand, thereby facilitating adjustment and settingof the unit.

The benefits and advantages ,of the invention will be more fullyunderstood upon reference to the detailed description set forth belowwhen taken in conjunction with the single sheet of drawings annexedhereto, in which:

Figure 1 is a perspective view of an instrument housing showing one formof a receptacle and cover, together with the improved clampingarrangements forming therewith the subject invention. In this view, theparts are shown with the cover clamped in place on the receptacle.

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arrangement shown in Figure 1, illustrating the coaetionbetween theflange engaging portion and the mounting means therefor, The parts areshown in the nonclamping position.

Figure 4 is a view similar to that shown in Figure 3 but with the partsshown in the intermediate position just prior to initiation of clampingforces.

Figure 5 is a view similar to Figures 3 and 4 but with the parts shownin the clamping position. 7

' Figure 6 is a composite partial view, in elevation, of the parts shownin Figures 3, 4 and 5, showing the three positions of the flangeengaging portions superimposed on one another.

Referring now to Figure 1, there is shown an instru ment housingincluding the receptacle 7 and the cover 8.

The receptacle is shown as a substantially cylindrical body having oneof its ends open to permit installation of any suitableinstrumentmechanism. The particular receptacle shown is used for a timeswitch, and the posts 9 are provided within the receptacle on which tomount the time switch mechanism. A conventional threaded conduitextension 11 projects downwardly from the receptacle to permit wiring ofthe device in the usual manner.

As best shown in Figure 3, the receptacle 7 is provided with a shoulder12 surrounding its open end, and this shoulder has the seat 13 which maybe provided with a groove 14 into which may be cemented a sealing gasketin the form of the sponge rubber ring 15.

The cover 8 has an outwardly extending flange 16 surrounding its openend, and this flange is adapted to fit onto the shoulder 12 and abutthat portion of the receptacle forming the shoulder seat 13. The coveris thus substantially tangentially with respect to the side walls of thecover 8. The portions 19 have their extremities curving 'rearwardly toform small arcuate sections 22, which in turn have their tips 23 bentoutwardly at right angles to I provide pivotal arrangements for theclamping member 17.

Thus, the clamping member 17 is a substantially U- shaped member, andbeing formed of a relatively stiff steel wire, it is resilientlydeformable in that any slight changes in configuration caused during theclamping operation of the member do not permanently change theconfiguration but only for so long as the deforming forces, are applied.It is to be noted that the flange engaging portions are said to havetheir extremities curving rear- Wardly, and this results from the factthat when the handle moves ina coveraclamping direction, it is said tobe moving forward, in which case the direction of curvature is properlydesignated as rearward.

Cooperating with the clamping member 17 are the oppositely disposedmounting means 24 in the form of a pair of ears projecting upwardly fromthe receptacle 7 and formed integrally therewith, although such'integralconstruction is not necessary for. the proper functioning The portions19 have straight sections 21 which in the clamping position are arrangedof the mounting means. Here again, the mounting means are similar to oneanother, and like numbers have been assigned to the drawings to indicatesimilar elements. These mounting means are provided with suitableapertures 29 cooperating with the pivot shafts 23. As is best shown. inFigures 3, 4 and 5, the mounting means 2 5, which is the left hand meansshown in Figure 1, has the first and second cam surfaces 25, 26,respectively, which cooperate in a unique manner with the flangeengaging portions of the handle 17. The cam surface 25 is formed by aridge member shown inclined downwardly toward the shoulder seat 13 froma point substantially opposite aperture 29 and the cam surface 26gradually curves inwardly and rearwardly away from aperture 29 andcontinues until it issubstantially parallel to the side wall of thecover 8.

The manner of cooperation can be best described by following thecoaction of the parts as the handle is retated from the non-clampingposition shown in Figure 3 through the intermediate position shown inFigure 4 to the. final clamped position shown in Figure 5. These viewsare also shown in superimposed form in Figure 6. In the description ofthe mode of operation following, only one flange engaging section willbe considered, it being understood that the two sections function in asimilar manner.

Starting with Figure 3, we see that the arcuate section 22 is slightlyabove the cam surface 25, such that the tip 23 projects through theoutside wall of the mounting means 24. In this position all parts of theclamping member overlie portions of .the receptacle and have no contactwhatever with the cover 8, and the cover may be easily removed and themechanism within the receptacle may be adjusted, serviced, repositioned,or the like.

When it is desirable to close the housing, the cover. may berepositioned on the receptacle such that its flange 16 rests upon theshoulder seat 13 and the clamping.

member is then rotated upwardly or forwardly in a coverclampingdirection. For about the first 90 degrees of pivotal motion, the arcuatesection 22 will be moving across the cam surface. 25, and since this camsurface is inclined inwardly towards the. flange lti, between it and theaperture 29, the effect of such motion will bring the arcuate sectionabove the. cover flange 16. To accommodate this motion, the tips 23 willslide axially inwardly during the aforesaid pivotal motion. Thisposition is shown in Figure 4, where the arcuate section 22 has justcleared the cam surface 25.

Continued pivotal motion of the clamp 1'7 through an angle of about 45degrees will cause portions of the arcuate section '22 to move acrossthe cam surface 26, and since this cam surface is inclined inwardlytoward the side walls of the cover, the arcuate section will movefurther inward until it contacts the flange 16. In a like manner, thearcuate section on the opposite side of the cover will also contact theflange 16 and the cover side walls will be engaged by portions 22a ofthe handle. This point of engagement with the side wall will be slightlyforward of the aperture 29 and will correspond to a distance between theside walls that is less than the distance between them taken across theaperture 2.9. The handle 17 is formed so that the normal distancebetween the side wall engaging portions 22a corresponds to the aforesaidlesser side wall spacing, so that any tendency for the portion 22a tomove toward aperture .29 will cause the handle to be slightly spread bythe cover side walls. With the handle forward so that its. outer endsare biased slightly toward each other, this action insures that thearcuate sections tightly grip the cover and align and center it on itsshoulder seat. This is an important. advantage in that it permits arather loose fit between the cover flange 16 and the shoulder 12 andprevents any possibility of the arcuate section getting between the edgeof flange 16 and. the lower portion of the side wall. of. shoulder. 12..Thus, we haveafirst, dc.- forming action that does some clamping but isprimarily relied upon to align and center the cover on the receptacle.Since the rearmost portion 22b of section 22 is offset outwardly, asshown in Figure 2, continued pivotal motion adds to the aforesaid effectand enhances the aligning action.

The final clamping and positive locking takes place when the straightsection 21-comes down on the cover. flange 16, and this position is bestshown in Figures 5 and 6. A second. deforming action takes place duringthis phase of the clamping cycle and in this instance deformation takesplace in the arcuate section 22 to generate forces in the wire thatpositively lock the cover in place. Thus, the normal ofiset spacingbetween the straight section 21 and the tip 23 is greater than thedistance between aperture 29 and the top surface of cover flange ifi.When the handle comes down flat, the arcuate section must becompressed.to allow the parts to fit and this compressing force furnishes the.necessary clamping and locking forceto effectively. hold the coverinflplace.

Thus, it is seen that a positive clamping action is achieved and thatthe clamping member is virtually selflocking in the clamped position. Toenhance'the selflocking characteristic suitable .detents in the form ofgrooves 27 substantially parallel to the shouldered seat 13 are providedadjacent the forward extremity of the 'base of each of the mountingmeans, into which por-- tions of the member 17 snap. It is-to be notedthat the forward extremity of the base of the. ears 2d curves inwardlyslightly whereby its inner wall intersects the wire clamping member whenit. moves into the clamping position; such intersection permits themember 17 to snap into the grooves 27 to form a detent therewith. It isto be noted further that the. clamping forces developed drive the flange16 against the gasket 14 to thereby efiec tively seal the housing andmake itsubstantially weatherproof.

As is best seen in Figure 1, the receptacle 7 is provided with anapertured ear 28 contiguous to the handle 17 when it is in thecover-clamping position. This arrangement' will permit. the use of aconventional instrument seal of the type that is used to indicate anytampering with the device.

The normal position for installing the aforementioned instrument housingis indicated in Figure 1, wherein the sealing ear28 isat the top of thedevice. Should anyone desire to remove the cover, it is only necessaryto remove the seal and. grasp the clamping handle 17 with. one hand andpull downwardly until the member rests. upon the bottom section ofshoulder 12. The cover. can then be grasped by the hand and removed.Upon reassembly of the parts the coven is placed in position overlyingthe shoulderiseat 13, and the clamping handle 17 is then pulled upwardlyuntil the parts are securely and positively locked in place. Operationand use are thus .quite simple, and the cover may be removed andreplaced Therefore, while a particular embodiment of the subjectinvention has been shown and describedherein, it is in the nature ofdescription rather than limitation, and

it will occur to those skilled in. the: art that various changes,

modifications, and cornbinationsxmay be made within the provinceof: the.appended claims, and without departing either in spirit or scope fromthis invention in its broader aspects.

The covers in many instances are What we claim as new and desire tosecure by Letters Patent of the United States is:

1. lAIl instrument housing comprising, in combination: a receptaclehaving an opening therein, a shoulder formed in said receptaclesurrounding said opening, a rem-ovably mounted cover for said openinghaving side walls and an outwardly flanged portion resting on saidshoulder, a pair of apertured ears projecting upwardly from saidshoulder on opposite sides of said cover, and a substantially U- shapedclamping wire pivotally mounted on said ears, each of the ends of saidwire including rearwardly curving arcuate sections which in turn havetheir tips bent outwardly at right angles thereto, said tips beingrot-atably and slidably mounted in said apertures, said clamping wirehaving a non-clamping position out of engagement with said cover, saidclamping wire having a clamping position upon pivotal movement from saidnon-clamping position, said ears having a first cam surface inclineddownwardly between said aperture and said shoulder, said arcuate section cooperating therewith to slidably move said tips toward said cover,said ears having a second cam surface inclined inwardly and rearward-1yfrom said apertures, said arcuate sections cooperating therewith tomaintain a clamping pressure on said side walls when said wire ispressed downwardly in a cover clam-ping direction, said clampingpressure serving to align said cover on said receptacle.

2. An instrument housing comprising, in combination: a receptacle havingan opening therein, a shoulder formed in said receptacle surroundingsaid opening, a removably mounted cover for said opening having sidewalls and an outwardly flanged portion resting on said shoulder, meansfor selectively clamping said cover to said receptacle, said meanscomprising a pivotally mounted handle including a pair of interconnectedflange engaging wire sections arranged tangentially on opposite sides ofsaid cover, said wire sections having rearwardly curving arcuate camfollower sections which in turn have their tips bent outwardly at rightangles thereto, and apertured mounting ears fiormed on said shouldersfor rotatably and slidably receiving said wire tips, said ears includinga first cam surface inclined downwardly between said aperture and saidshoulder and including a second cam surface inclined inwardly andrear-wardly from said apertures toward said shoulders, said arcuate camfollower sections cooperating with said cam surfaces upon pivotal motionof said wires whereby said flange engaging sections are moved inwardlyover said cover flanges and downwardly onto said cover to clampinglyengage said cover flanges and said cover side walls.

3. The combination defined by claim 2 wherein said shoulder has a groovetherein underlying said cover flange and a resilient deformable sealingmember is placed in said groove to cooperate with said cover flange toetfectively seal said housing.

4. The combination defined by claim 3 wherein said mounting means alsoincludes a forwardly disposed groove cooperating with portions of saidwire sections to form a detent therewith to retain said wire sections insaid clamping position.

References Cited in the file of this patent UNITED STATES PATENTS477,955 Patterson June 28, 1892 597,051 Danz Ian. 11, 1898 1,026,093Johnson May 14, 1912 2,572,629 Kolell Oct. 23, 1951 2,666,092 BalzerJan. 19, 1954

